There’s been remarkable progress in recent decades in the efficiency of gas furnaces: new models require a minimum efficiency of 95%. But Canadians need both heating and cooling so the residential market is taking a closer look at heat pumps, which not only deliver two to three times the efficiency of a gas furnace but also provide cooling in summer.

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Gord Cooke, President of Building Knowledge Canada, has seen progress in both conventional and heat-pump technology over his career. In an article originally published in Spring 2023 in Better Builder Magazine, Gord cautions that getting the most out of a heat pump depends on sizing it to the building and its systems.

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Sizing for heat vs. cold – According to Gord, the fact that heat pumps provide both heating and cooling poses a challenge in the Canadian climate. Heating usually draws most of the energy but if only the heating load is considered, the heat pump will be oversized for cooling purposes, leading to poor humidity control in summer. This could be coupled with a dehumidification system, but that might be less cost effective. So, Gord stresses the need to do a comprehensive calculation of the home’s heat loss and gain before selecting a heat pump, which is required for most building permits but is desirable even when doing an HVAC system retrofit or renovation. As a general rule, he says that one can safely size a heat pump for 125% of the required cooling capacity. 

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Working with other systems – Heat pumps don’t usually work alone; they’re integrated with back-up heating, such as a conventional furnace or an add-on heating coil, attached to a tankless water heater, for example. As Gord puts it, if efficiency is the goal, then a builder will want the heat pump to be the main source of heat as often as possible. This depends on understanding how much heating is required to make up the shortfall in very cold temperatures (if a new furnace is being considered) or how much an existing furnace is already putting out. 

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Dynamic control – Gord also suggests that, when installing heat pumps, builders take advantage of some of the newer thermostats, which can look at both temperatures and energy prices in real time and make intelligent decisions on when to run the heat pump and furnace. 

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Not everyone can afford a heat pump yet, but models continue to improve, and widespread adoption is driving prices down. Moreover, the drive for Canada to reduce greenhouse emissions is becoming more and more urgent. So, heat pumps should be considered as part of any new home design, or any energy retrofit.

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Building Knowledge Canada helps builders and contractors understand how heat pumps can best interface with home heating and cooling systems. Get in touch to see how we can support your design and business goals.

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